In a medium pot put the chopped onion, entire can of diced Tomatoes with Onion & Peppers and Green Chile and all the chicken. You will have to add just enough water to make sure the chicken is almost covered. Salt to taste. Simmer on a low-med heat for about 30 min.
When chicken is done, strain liquids keeping everything else. Let cool enough so you can handle it. Once cooled, break apart the chicken until it shredded. Mix chicken with all the rest of the veggies.
In your favorite 10x10 bake ware, pour a small amount of the enchilada sauce to just cover the bottom. Take 1 corn tortilla and spread refried beans on it (like you would peanut butter on bread) using 1/8 of the can of beans. Place this on the bottom of the baking dish, bean side up, and repeat 3 more times so the bottom is evenly covered.
Using ½ of the chicken mix spread evenly over tortilla. Then layer with a little less than ½ of the bag with the Queso cheese. Use a little more enchilada sauce to wet the layer. Then do it again with 4 more tortilla with refried bean, then chicken mix, cheese & sauce.
Top with the last 4 tortilla, cover with enchilada sauce and then the last of the Queso cheese and the cheddar cheese.
Bake for 30-40 min @ 350 degrees.